need help
 

I have a 1984 cutlass supreme brougham 307. i been having a few problems that i dont know how to fix. first my interior light dial only works when you turn it right up to high no inbetween. and another is the light in my glove box doesnt turn on when i open it only when i turn my night lights on it works and shows through the cracks.My tach stays on 1000rpm when i shut my car of but when i turn it goes back down to zero, and it jumps around when i move my heater/ac controls. and one more, my cruise control wasnt hooked up and i have no idea where the female end of it is and what size fuse is it, the origanal owner disconected it i think. any ideas ?